OF the class of 19 women in grade 4 at Tagrobavi high school in western Afghanistan, 11 are married, most of them with children.
In normal times the starting age in this grade would be 10. But in Afghanistan, 23 years of wars coupled with the Taliban's ban on education for girls and teaching work for women have left a generation scrambling to restart at school.
"The nightmare of the population bubble is a special factor here," said Eric Laroche, head of UNICEF operations in Afghanistan. "We are facing the strange situation where half of all kids, regardless of age, are in grade 1."
In Herat, not far from the border with Iran, the city ran catch-up classes for two months before the start of term. The target was 10,000 students of grades 2-12, but 22,000 turned up at four schools and they had to be taught in three shifts.
"Now we take students regardless of their age and whether they are married and have children," said Musa Naeed, UNICEF's education officer in Herat. "In grade 3, for example, we have many women with three kids. They are aged anything from 16 to 25."
Given the dire conditions of the buildings and drastic shortage of teaching materials, there are scant resources available for adult literacy to relieve pressure on the schools. A survey in December found that four out of five schools in Herat had been destroyed.
Bismillah Bismill, Herat's director of education, said: "We are planning more adult literacy classes but we have problems because of lack of facilities and cash. If we had the facilities we would start right now."
He said that whenever a suitable teacher can be found, new courses are starting up. "Around five or six thousands adults are doing literacy courses and we are still getting more people registered. But we don't have enough textbooks. And we've not had time even to talk about adult education yet."
The pressure will remain on schools as the bubble of catch-up pupils rises through the system.
"The challenge ahead is just crazy," said Mr Laroche.
With three of the four million Afghans who fled to Iran and Pakistan still to return, not to mention vast numbers of internally-displaced people who are camped elsewhere in Afghanistan, the nightmare can only get worse.
Schools packed to the gills with 10,000 or more pupils - with half of them accommodated in tents - have created an unmatchable demand for trained teachers. But these are hard to find in a country that banned women - two-thirds of its school staff - from working.
To help plug the gap, Herat province has hired 2,500 18-year-old pupils and UNICEF has set up a new teacher-training college.
Even those who trained before the ban are not equipped to deal with the dramatic differences of age found in the same class.
In the ruins of Soofi Islam Mayen school in war-torn Kabul, 15-year-old Dino is frustrated at having to study topics too babyish for her age.
She reached grade 3 before the Taliban but then had to stay at home for five years. "If I had not been deprived of my education I would have been in grade 9," she says, sitting on a row of bricks because there are no chairs.
On the board is an exercise in Dari, her second language. It is a story about how a pigeon saw an ant struggling in the water and fetched a leaf to save it. One day in the desert the pigeon was about to be shot, when the ant saved its life in return by biting the hunter's foot.
"There are problems with teaching multi-age classes," says her teacher Zachia Sadiqi, 35. "The older ones ask me to teach more but the smaller ones cannot follow."
The pupils are allotted their starting grade after taking a simple test. At Soofi Islam there are six and 16-year-olds in the same class.
But for many of the older students at Tagrobavi school, none of this dampens their joy at being given the chance to study at all.
Lida, 22, who missed six years schooling, said UNICEF helped her teach her sisters at home under the Taliban by giving her textbooks, chalk and a blackboard. But now she has a chance to finish her own education. She said. "I want to become a professional engineer to serve my country."
Credit Card hotline 08457 312 312